Novel substituted 3-(alpha-carbamoyloxy-lower alkyl)-4, 7-indoloquinones



United States Patent 3 265 698 NOVEL SUBSTITUTED so.-cARisAMoYLoxY LOWER ALKYL)-4,7-INDOLOQUINONES George Rodger Allen, Jr., Old Tappan, N.J., and John no; R is hydrogen, lower alkyl or phenyl and R is hydrogen, lower alkyl, lower alkenyl, phenyl lower alkyl, phenyl, halo-substituted phenyl, :lower alkoxy-substituted phenyl, naphthy-l, w-di(lower alkyl) aminoalkyl, lower cy- Frank Poletto, Nanuet, N.Y., assignors to American 5 cgoalkyl w'(cyano)lower (lower alkylthioflower Cyanamid Company, Stamford, Conn., a corporation of a yfl wer alkyl, fl-(hydroxyflower Maine alkyl, -(hydroxy)lower alkyl or amino. Suitable lower No Drawing. Filed Aug. 7, 1964, Ser. No. 388,312 alkyl, lower alkanoyl and lower alkoxy groups contem- 20 Claims. (Cl. 260-268) plated by the present invention are those having up to about 6 carbon atoms. Suitable w-substituted lower alkyl This is a continuation-impart of application Serial No. groups are those having f 2 to 4 carbon atoms. i 1 fi pc 1963, 110W aband011dedable lower alkenyl groups contemplated by the present T1118 lnYentloll relates to 116W Organlc COIIIPOIIPdS and, invention are, for example, allyl, methallyl and Z-butenyl. more particularly, is concerned with novel substituted 3- ph lower lk may be lifi d by -l h f- Y Y- Y lndoloqlllnofles and 15 ethyl, etc. Suitable halo-substituted phenyl groups con- Wlth novel {methods 0f Preparing these compoundstemplated by the present invention may be, for example, novel substituted 3-(a-carbamoyloxy-lower alkyl)-4,7-1n- -chl r -fluo and .o-bm o. Naphthyl may be doloquinonesof the present invention may be represented a-naphthyl or B-naphthyl, w-di(lOW61 alkyl) aminoalkyl is by the following general formula: exemplified by B-dimethylamino-ethyl and v-dimethylami- O nopropyl, while w-(hydroxy)1lower alkyl is exemplified by H Q 0 R ,B-hydroxyethyl and v-hydroxypropyl. Lower cycloalkyl Y may be cyclopropyl, cyclopentyl or cyclohexyl while halo- I gen is exemplified by chlorine, bromine and iodine. Z B R15 When R and R are taken together with nitrogen \N/ R15 I wherein A is hydrogen, lower alkyl, w-(halo)lower alkyl, Rm a1ky1thi0)1 0Wef y alkylsulfonl' suitable basic groups are N-lower alkylpiperazino, N-(wum)-10Wer ialkyl hahde, y y) 9 y hydroXy lower alkyl)piperazino, N-[(w-di-lower alkyl- Y -PY Y YN y 'alkyl, amino)lower alkyl]piperazino, morpholino, cyclopoly- P Y y B 15 hydrogen, lower alkyl, methyleneimino of from 2 to 5 carbon atoms and bishalomethyl, ammomethyl, hydr-oxymethyl, lower alkoxylower carboalkoxymethyl. y lower alkanoyloXymethyl, tetrahydropyfanyloxy- 5 The novel compounds of the present invention are oby' Q alkyl)cafbamoyloxymethyl, 3 tainable as crystalline materials having characteristic alkanoylthwmethyl, 'f Y Y PW- melting points and absorption spectra. They are apy y y y l a lower y lpreciably soluble in many organic solvents such as lower nomethyl, N4-10W61 Fllkylsemkcafbamnomethyl 0f alkanols, acetone, ethyl acetate, and the like. They are, cafbalanome'lhyl; Q 15 hydrogen lower y Y 18 Y- 40 however, generally insoluble in water. The novel comdfogel'l, Sf Y, lower 3, halogen, 31 pounds of the present invention are useful as antibacterial y l ammo, mOHOUOWBI' yn-{ agents. These compounds have been found to possess yb p y yfl l y -q, broad spectrum anti-bacterial activity in vitro. The minalkylaflllnohnonoflowel' yn l s y irnal inhibitory concentrations, expressed in gammas per amm0Il1Pm)m0110(10W6I alkynamlflo ',Y milliliter, of some. typical compounds of the present inalk ylamino, phenyl lower :alkylamino or polymethylenevention against various microorganisms when measured lIIlIIlO of from two to five carbon atoms; Z is hydrogen, by a standard turbidimetric precedure are set forth in lower alkyl, bromine, lower alkoxy, amino or methylamithe following table:

TABLE I Staph. aureus Staph. aureus 'Staph. Strept. sp., Pasteurella Strept. Klcbsz'ella Compound ATCC 13709 ATCC 14154 aureus 69 fl-hemolytie mutocida pyoganes pncumom'ae53 80 ATCC 8369 0-203 1-ethyl-B-hydroxymethyl-5-meth0xy-2,6-dimethyl-4,7-dioxoindole earbamate 1. 6 1. 6 1. 6 6. 25 1. 6 0. 8 1-ethyl-3-hydroxymethyl-5-methoxy-6-meth l 4,7-dioxoindole earbamate 0.8 1. 6 0.8 3.12 0.8 0.8 12. 5 l-ethyl-3-hydroxymethyl-methoxy-ZG- dimethy1-4,7-dioxoindole methylearbamate... 3. 12 3. 12 3. 12 12. 5 3. l2 1-ethyl-3-hydroxymethyl-5-methoxy-2,6-

dimethyl-4,7-dioxoindole amylearbamate. 25 25 50 l. 1-ethyl-3-hydroxymethyl-5-methoxy-2,6-

dnnethyl-4,7-dioxoindole phenylcarbamate... 6. 25 25 12. 5 12.5 25 O. 4 1-ethyl-3-hydroxymethyl-5-meth0xy-2,6-dimethy1-4,7 dioxoindo1e dimethylcarbamate.-. 3. l2 6- 25 6.25 12. 5 6.25 1-(2-flu0roethyl)-3-hydroxymethyl-5-methoxy- 2,6-din1ethyl-4,7-di0x0indole methylcarbamate 3.12 3.12 3.12 12. 5 a. 12 1.6 50 1-(Z-azidoethyl)-3-hydroxymethyl-5-methoxy- 2,G-dimethyll,7-dioxoindole methylcarbamate 3. 12 6. 25 6. 25 12. 5 6. 25 50 I-(Z-methylthioethyl)-3-hydroxyrnethy1-5- methoxy-2,6dimethyl-4,7-diox0indole methylearbamate 3. l2 3. 12 3. 12 12. 5 3. l2 1-(Z-hydroxyethyl)-3-hydroxymethyl-5-methoxy-2,6-dimethyl-4,7-di0xoindo1e methylcarbamate 1. 6 1. 6 1. 6 6. 25 1. 6 0. 8 25 TABLE I-Confinuod Staph. aureus Staph. aureus Staph. Strepi. sp., Pasteurella Strept. Klebsz'ella Compound ATCC 13709 ATCC 14154 aureus 69 fl-hemolyt 1c mutocida pyogenes pneumoniae 53 80 ATC O 8369 C203 1 -(Z-tetrahydropyranyloxyethyl)-3-hydroxymethyl-5-methoxy-2,6-dimethyl-4,7-dioxoindole methylcarbamate 12. 5 12. 5 12 5 50 3, 2 1-(2-ch10roethyl)-3-hydr0xymethyl-5-methoxy- 2,6-dimethyl-4,7-dioxoindole methylearbamat 6. 25 12.5 6. 25 25 6. 25 1. 6 1-ethyl-2,3-bis-hydroxymethyl-5-rnethoxy-6- methyl-4,7-dioxoindo1e 3-methylcarbarnate 0. 8 1. 6 1. 6 6. 25 1. 6 1. 6 12. 5 1-ethy1-2,3-bis-hydroxyrnethyl-5-meth0xy-6- methyl-4,7-dioxoindole 2,3-bis-methylcarbam e 8 3. 12 1. 6 12.5 o, 8 0. g 25 2-chloromethy1-l-ethyl-3-hydroxymethyl-5- methoxy-fi-methylt,7-dioxoindolemethylrb m te 1.6 1. 6 1. 6 12.5 12, 1, 6 12, 5 2-tetrahydropyranyloxymethyl-l-ethy hydroxymethyl-5-n1ethoxy-6 methylA 7- dioxoindole methylcarbamate 6. 25 12, 5 6, 25 3 12 2-hydroxyiminometl1yl-1-ethy1-3- methyl-5-meth0xy-6-methyl-4 7-dioxoiudo1e methylcarbamate L 6 6. 25 3. 12 12. 5 6, 25 25 2-carboxamido-l-ethyl-Ii-hydr ymethy methoxy-G-methyl-4 7-d1'0xoind0lemethy1- carbamate 6- 25 12. 5 6. 25 50 6. 25 50 1-ethyl-3-hydroxym methylarnino-2,6-

dimethyl-4,7-diox0indo1e carbamate 25 25 25 25 5 25 1-ethyl-3-hydroxymethyl-5-methoxy-2,G-dimethyl-4,7-diox0indole benzylcarbamate 1.6 12. 5 25 25 50 l-ethyl-3-hydroxymethy1-5-methoxy-2,6-dimethyl-4,7-di0xoindole Z-methylthiopropylcarbama 3. 1 6. 25 6. 25 12.5 25 1. 6 1-ethyl-3-hydr ethy methoxy-2,6-dimethyl-4,7-dioxoindole N-methyl-(3-dimethylaminopropyl) carbamate 1. 6 3.12 3.12 3,12 3,12 25 In addition, the novel compounds of the present invention possess activity both orally and parenterally against Staphylococcus aureus, strain Smith, infections in mice, Staphylococcus aureus, strain Smith, has been studied and described by J. M. Smith and R. J. Dubos in Journ. Expt. Med. 103, 87 (1956), at the Rockefeller Institute. Staphylococcus aureus, strain Smith, is coagulase positive, tellurite negative and is sensitive to tetracycline, penicillin, streptomycin, erythromycin, carbomycin, neomycin,

chloramphenicol and novobiocin in vitro. Attempts have been made for phage typing of this strain, but it has been determined that it is non-typable.

The effective dose at which 50% of the test animals were saved (ED was determined against Staphylococcus aureus, strain Smith, infections in mice by the subcutaneous route. The ED values thus determined are set forth for a representative group of compounds of the present invention in Table II below.

TAB LE II l-ethyl-3-hydroxymethyl-5-methoxy-2,6-dimethyl-4,7-dioxoindole carbamate 1-ethyl-3-hydroxymethyl-5-methoxy-2,6-dimethyl-4,7-dioxoindole methylearbamate.

Compound 1-ethyl-3-hydroxymethy1-5-methoxy-2,6-dimethyl-4,7-dioxoind0le ethylcarbamate 1-ethyl-3-hydroxymethyl l-butyl-3-hydroxymethyl-5-methoxy- 1,2-diethy1-3-hydroxymethyl-5-rnethoxy-6-methyl-4 ED mg./kg. of body weight carboxylate xyethyl carbamate dioxoindole v-hydroxypropyl carbamate: n droxoindole fl-ethoxyethyl carbarnate.

1-ethyl-3-hydroxymethy1-5-methoxy-G-methyl2-semicarbazanomethyl4,7 dioxoindolemethylearbainate fi-amin0-1-ethyl-3-hydroxymethyl-2,6-dimethyl-4,7-dioxoindole propylc 5-benzylamino-1-ethy1-3-hydroxymethyl-2,6-dimethy1-4,7-dioxoindole methylcarbamate 5-aziridino-l-ethyl-3-hydroxymethyl-2,6-dirnethyl-4.7-dioxoindole methylcarbamate... 5-ethoxy-1-ethyl-8-hydroxymethyl-2,6-dimethyl-4,7-dioxoindole methylcarbamate 1-ethy1-3-hydroxymethy1-5-methoxy-2-methyl-4,7-dioxoindole propylcarbamate 1,6-diethyl-3 hydr0xymethyl-5-meth0xy-2-methy1-4,7-dioxoindole methylcarbamate 1 Approximate.

arbarnate 5 6 The novel compounds of the present invention may be fLXXXIV) with a lower alkyl, lower alkenyl, or aryl prepared by the series of reactions set forth in the followisocyanate or with a diphenylcarbamoyl chloride. ing reaction scheme: Treatment of the compounds of type (LXXXVI) with o II Ite II Ilia (I? BIT- -oHo1-I n1 oH-o-o-o-(Jm,

s I R13 R2 'Rl: RI

\N/ N n 1 Y I LXXXIV LXXXV I I l 3 0 R R 0 R 0 l6 6 1B R1z 3H0( JN A LXXXVI LXXXVII wherein R is hydrogen, lower alkyl, w-halo-lower alkyl, a lower alkylamine and for more prolonged periods with w-lOWClPillkYlEllkYlllllO lower alkyl, 'w-tetrahydropyranylammonia or various secondary amines affords the 5- oxy lower alkyl or w-azido lower alkyl; R is hydrogen, amino compounds of type (LXXXVII). Certain of these lower alkyl, ca-rboxamido, lower alkoxycarbonyl, or tetracompounds, particularly the mono alkylamino derivatives,

hydropyranyloxymethyl; R is hydrogen or lower alkyl; may be selectively hydrolyzed to the S-hydroxy-para- R is hydrogen, lower alkyl, alkoxy, halogen or lower quinones of type (LXXXVII) where R is hydroxyl. alkylthio; R is hydrogen, lower alkyl, halogen, lower These S-hydroxy-pa-ra-quinones may be alkylated in the alkoxy, amino, or lower alkylamino; R is hydrogen, presence of a base such as potassium carbonate with an lower alkyl or phenyl; R is hydrogen, lower alkyl, lower alkylating agent such as methyl sulfate to give the alkyl, lower alkenyl, phenyl lower alkyl, phenyl, halosub- S-alkoxy-para-quiuones of type (LXXXVI). stituted-phenyl, lower alkoXy-substi-tuted phenyl, naphthyl, These compounds wherein R is w-hydroxy lower alkyl (ii-di(lower alkyl)aminoalkyl, hydroxy-lower alkyl, cycloor R is hydroxymethyl may be prepared by mild acid alkyl, w-cyano lower alkyl, w-lower alkylthio lower alkyl, hydrolysis of the corresponding tetrahydropyranyloxyw-IOWCI alkoxy lower alkyl, or amino; and R and R methyl compound. Those compounds wherein R is wtaken together with nitrogen (di-lower alkyl sultoniumflower alkyl halide or wherein R is w-(tri-lower alkylammonium)lower alkylamino halide may be prepared by treatment of the correspond- R15 ing w-(lower alkylthio)lower alkyl or w-(di-lower alkylamino)lower alkylamino compound with a lower alkyl halide.

Those compounds (wherein R is (lower alkanoyloxy) methyl or (N-lower alkylcarbamoyloxy)methyl may be i alkylpiperalino, cyclopolymethylfinelmlno C011- prepared by treatment of the corresponding hydroxytaining tWO t0 five carbon atoms, bis-lower carboalkoxycompound a lower alkanoic acid anhydride y N-( Y )P P or a lower alkyl isocyanate, respectively. Those comdfOXY lower ynp p mofpholino; and 17 is pounds wherein R is formyl may be prepared by treaty y, amino, monoflower alkynamino, y y ment of the eorm ondin hydroxymethyl compound amino, P y lower alkylamino, Y Y lower y with an oxidizing agent, preferably manganese dioxide. amin w yh YU J- Those compounds wherein R is hydroxyiminomethyl, lower alkylamino, Polymethyleneimino Containing O-lower alkylhydroxyimino methyl, or semicar-bazano from two to five carbon atoms. In accordance with this methyl may be prepared by treatment of the OOIIresp0nd reaction S h me, treatment of a y Y y ing formyl compound with hydroxylamine, O-lower alkyl indoloqu no e With P 31 chlorofofmate hydroxylamine or semicarbazide, respectively. Those furnishe the COIIeSPOIIdiHg -p y y ycompounds wherein R is cyano may be prepared by dey derivatives Th$e esters are p hydration of the corresponding hydroxyiminomethyl comularly useful for the preparation of some of the novel pound with a reagent such as thionyl chloride or by compounds of this invention. Thus, on treatment with a treatment of the corresponding compound wherein R lower alkylamine these esters furnish the 3-(a-lower is formyl with O,N-bis-trifluoroacetylhydroxylamine. alkylcarbamoyloxyalkyl) 5 lower alkylamino 4,7- Those compounds wherein R is chloromethyl or indoloquinones (LXXXVII), while treatment with ambromomethyl may be prepared by treatment of the cormonia or a di(lower alkyl)amine is productive of the responding hydroxymethyl compound with areagent such 3-(u-carbamoyloxyalkyl) or 3-(u-dialkylcarbamoyloxyas thionyl chloride or thionyl bromide. Those comy derivatives D- Moffiovel', in COmpounds wherein R is fluoromethyl, lower alkoxymethyl pounds of type (LXXXVI) may be prepared by treator lower al-lcanoylthio-methyl may be prepared by tre-at- I ment of a 3 (a hydroxyalkyl) 4,7 indoloquinone ment of the corresponding chloromethyl compound with 7 8 silver fluoride, a lower alkoxide orta lower thiolakanoic acid salt (e.g., potassium thiolacetate), respectively. R6 R6 Those compounds wherein R is aminomethyl may be pre- R O I l pared by treatment of the corresponding chloromethyl compound with ammonia. 5 R R R R The requisite 3-(a-hydroxyalkyl)-4,7-indoloquinones 4 2 2 may be prepared in several ways, principally in accord- I I ance with the following reaction scheme: 1 VIII IX FLOWSHEET A H NHRi wherein R R R and R are lower alkyl and R and R1NHz+ RzCCHzCOORg R2C=OHC0OR3 R are hydrogen or'lower alkyl. In accordance with r I II In this reaction scheme, the indole system (V) is developed by condensation of a substituted 1,4-benzoquinone (IV) 0 with a substituted amino-crotonate ester (III). The 1at l 1o NHR! ter reagent is prepared by the interaction of an appro- R4 HO COOR3 priiate amine (I) with a ,B-ketoester (II). The resulting 320:0]100033 5-hydroXy-3-indolecarboxylic ester (V) may be con- R4 verted into other useful S-hydroxyindoles (IX). Thus, I I decarbalkoxylation of the 3-indolecarboxylic ester (V) 0 R1 gives the hydroxyindoles (VI); a particularly useful rea- III IV V gent for this transformation being hydrochloric acid. The resulting 5-hydroxyindole (VI) is then O-alkylated to furnish the 5-a1koxyindole (VII). Treatment of this product with phosphorus oxychloride and dimethylform- R50 HO amide or with an alkanoyl anhydride and alkali metal alkanoate affords the corresponding 3-carboxaldehyde or R4 R2 R4 3-acyl derivative (VIII). The ether function in this f class of compounds is then cleaved to give the important R1 S-hydroxyindoles (IX); this cleavage may be effected with VII VI hydriodic acid or aluminum chloride in boiling xylene.

l As set forth in the following reaction scheme:

FLOWSHEET B R I R 7 7 Ha i=0 O= (5:0

1 Br- \N/ R: R4- \N R2 is 1'1, X XI 0 CR3 0R8 R9 I'M filHz HO C: RaO- C=O R CORs l I R4 \N/ R2 R; I \IF/ R: R4 I l R2 6 1 12 ORB R1 0R8 R1 XIII XII XIIa i R l R 7 6 mo (i=0 R50 A (11101: II I! l J R4 \(\N R: R4 \/\N R: l I l l 0 R1 0 R1 Wheiein R R R and R are lower alkyl; R; is hydrogen, lower alkyl or lower alkoxy; R is lower alkanoyl and R is hydrogen, hydroxy or lower alkyl; the previously described S-hydroxyind-oles (X) may be converted into 4,5-ortho-quinones (XI) by any of several methods Well known to the art for the conversion of a phenol into an ortho-quinone. Particularly useful for this transformation is potassium nitrosodisulfonate (Fremys salt) which accomplishes this conversion in one step. Conversion of an ortho-quin-one (XI) into the paraquinone (XIII) is achieved via an intermediate 4,5,7- lower alkanoyloxyindole (XII), prepared by treating the ortho-quinone with a lower alkanoyl anhydride and a strong acid such as boron trifluoride. When the orthoquinone (XI) contains a 3-acy1 substituent, concomitant enol acylation of the carbonyl group occurs to give (XIIa). The triacyloxyindoles (XII and XIIa) then may be hydrolyzed to the corresponding trihydricphenols, which on oxidation with air or other oxidizing agents, furnish the corresponding S-hydroxy-para-quinone (XIII). During the hydrolysis step, a 3-carbalkoxy group is hydrolyzed to the corresponding acid, and the enol acylate (XIIa) formed in the acylation of an ortho-quinone containing a 3-acyl substituent is hydrolyzed to regenerate the 3-acyl substituent. The 5-hydroxy-para-quinones (XIII) may be O-alkylated to give the corresponding 5- alkoxy-para-quinones; of particular value for this con version are the dialkyl sulfates and tetraalkoxymethanes. The alkylation of a S-hydroxy-para-quinone containing a 3-ca1 boxy substituent produces the 3-carbalkoxy-5- alkoxy-para-quinone. Reduction of the S-alkoxy-paraquinones (XIV), followed by oxidation of the hydroquinone thus formed, gives the important 3-(u-hydroxyalkyl)-para quinones (XV). When the S-alkoxy-paraquinones (XIV) have a carbalkoxy substituent in the 3- position, lithium aluminum hydride is used for this reduction. For those S-alkoxy-para-quinones (XIV) having a formyl or acyl substituent at the 3-position, sodium borohydride is particularly useful for this reduction.

The important 3(uahydno xyalkyl)-4,7-indoloquinones may also be prepared as set forth in the following reaction scheme:

FLOWSHEET C XVI R (I) R5 l l CH CHZCOCOOR I I O z N 02 XVII XVIII RsO- R5 fl- E R4 lf R4 ITI C O O XX XIX wherein R R R and R are lower alkyl; and R R and R are hydrogen or lower alkyl. This sequence is of particular value for the preparation of those 3-(uhydroxyalkyl)-4,7-indoloquinones bearing hydrogen at the 2-position, i.e. compounds such as (XXV) wherein R is hydrogen. In accordance with this reaction scheme an ortho-alkyl-para-nitro-meta-cresol (XVI) is treated with an alkylating agent such as an alkyl halide or dialkyl sulfate in the presence of base to give the alkyl aryl ether (XVII). Base-catalyzed acylation of (XVII) with a dialkyl oxalate affords the glyoxylic ester (XVIII). Reductive cyclization of this ester furnishes a 6-alkyl-S-alkoxy-Z-indolecarboxylic acid (XIX); this reductive cyclization may be achieved with zinc dust in acetic acid, ferrous ammonium sulfate, sodium hydrosulfite or the like. Decarboxylation of the acid (XIX) then gives the indole (XX) which on treatment with phosphorus oxychloride and dimethylformamide or a dimethylalkanoylamide furnishes the S-formylor 3-acylindole (XXI). On treatment with a strong base such as potassium hydroxide or sodium hydride and an alkylating agent such as an alkyl halide or a dialkyl sulfate, the 3- forrnyl and 3-acylindoles (XXI) afford the corresponding l-alkyl derivatives (XXII). These compounds (VIII and XXII) are converted into their 4-nitro derivatives (XXIH) by the action of an alkali metal nitrate in sulfuric acid or fuming nitric acid in acetic acid. On hydrogenation 1-1 in the presence of a noble metal catalyst the 4-nitroindoles (XXIII) are transformed into the 4-amino-3-(ahydroxyalkyl)indoles (XXIV), which on treatment with an oxidizing agent such as Fremys salt give the requisite 12 (corresponding to XXIII) undergoes concomitant deacylation upon reduction to the 4-aminoindole (corresponding to XXVI). After oxidation of this substance to the paraquinone (corresponding to XXVII) the hydroxymethyl 3-(u-hydroxyalkyl)-4,7-indoloquinones (XXV). substituent is converted into a 2-tetnahydropyranyloxy- Alternatively, the 4-nitroindoles (XXHI) may be methyl derivative by reaction with dihyd-ropyran in the treated with a chemical reducing agent, e.g., ferrous ampresence of an acid catalyst. Sodium borohydride reducmonium sulfate or iron in acetic acid, to give the cortion followed by ferric chloride oxidation then gives a responding 4-aminoindoles (XXVI). On treatment with 3-(a-hydroxyalkyl)-4,7-indoloquinone having a 2 tetra- Fremys salt these last compounds furnish the correspond hydropyranyloxmethyl substituent. ing para-quinones (XXVII). Reduction of the 3-formyl Alternatively, the indole esters (XXIX) of Flowsheet D or 3-acyl substituents in these compounds with sodium may be converted into their 3-formyl or 3-acyl derivatives borohydride and oxidation of the intermediate hydro- (XXXII) by phosphorus oxylchloride and dimethylformquinone with acidic ferric chloride gives the 3-(oc-hyamide or dimethylalkanoyl amide. Upon treatment with droxyalkyl)-4,7-indoloquinones (XXV). fuming nitric acid in glacial acetic acid the compounds of Certain of the requisite 3-(oc-hydroxyalkyl)4,7-indolotype XXXII give the 4-nitroindoles (XXXIII) in mixture quinones may also be obtained in accordance with the with the 4,5-indoloquinones (XXXIV). These last comfollowing reaction scheme: pounds may be transformed into 3-(u-hydroxya1ky1)-4,7- indoloquinones having a 2-carboalkoxy substituent in ac- FLOWSHEET D cordance with procedures outlined in Flowsheet B. The

R;- \N u-COOH R4 \ITI/ OOOR3 R4 \N/ COOR3 III H I ll XIX XXVIII XXIX R4 \N CHzORs R4 lTI -CHzOH R4 COOR3 1 11 R1 R1 XXXI XXX XXXII lie [I 1] R50 0:0 0: 0:0 R4 COOR3 R4 1? ODOR; R1 R1 XXXIII XXXIV t" R50 o=0 R 0 0:0

R4- \ITI/ COOH R4 \N GONH: R1 1 XXXV XXXVI wherein R and R are hydrogen or lower alkyl; R R and R are lower alkyl; and R is lower alkanoyl. In accordance with this flowsheet, esterification of the acids of type XIX (Flowsheet C) gives the corresponding ester (XXVIII). Upon treatment with an organic base and a lower 'alkyl sulfate these esters are converted into the corresponding N-alkyl compounds (XXIX). Reduction of the latter compounds with lithium aluminum hydride gives the corresponding 2-indolylmethanols (XXX), which on treatment with a lower alkanoic acid anhydride in pyridine are transformed into compounds of type XXXI. These last compounds may be converted into the important 3-(a-hydroxyalky1)-4,7-indoloquinones as described in Flo Wsheets A and C. In this conversion, the 4-nitroindole 4-nit'roindoles (XXXIII) may also be converted into 3- (u-hydroxyalkyl).-4,7-indoloquinones containing a 2-car- 'boalk oxy substituent as illustrated in Flowsheet C. Additionally, the 4-nitroindoles (XXXIII) are hydrolyzed by methanolic solutions of inorganic bases to give the 4-nitroindole acids (XXXV) which are converted into the amides (XXXVI). The latter conversion is best effected by conversion of the acids (XXXV) into a mixed carbonic acid anhydride, which on treatment with ammonia gives the amides (XXXVI). These compounds are then transformed into 3-(a-hydroxyalkyl)-4,7-indoloquinones having a 2-carboxamido substituent as illustrated in Flowsheet C.

Certain of the requisite 3-(a-ketoalkyl)-4,7 indolo- 13 quinones may be obtained in accordance with the following reaction scheme:

FLOWSHEET E wherein R R R and R are -lower alkyl; R is hydrogen or lower alkyl; R is halogen, azido, lower alkylmercapto, thiocyano, lower alkanoyloxy, and hydroxy; and n is an integer greater than 1. As illustrated in this fiowsheet, use of an w-hydroxyalkylamine in the processes described in Flowsheets A and C gives the important 4- aminoindoles (XLVI) and 4-nitroindoles (XLV). These compounds are then converted into the w-substituted alkyl indoles (XLVII) and (XLVIII) on treatment with an inorganic halide, azide, lower alkylmercaptide, thiocyanate or lower alkanoate in an inert solvent such as acetone or dimethylformamide. The resulting 4 nitroindoles (XLVIII) are then reduced to give the 4-a-minoindoles (XLVII). When the latter compound contains a .l-(wlower alkanoy1oxy)alky1 substituent, it is treated with an inorganic base to give a 4-aminoindole (XLVII) having a l-(a -hyd-roxyalkyl) substituent. On reaction with dihydropyran in the presence of acid these compounds give 4-arninoindoles (XLVII) having a l-w-tetrahydropyranyloxy)alkyl substituent. The resulting 4-aminoindoles (XLVII) are then converted into 3-(a-hydroxyalkyl)-4,7- indoloquinones having l-(w-substit-uted alkyl) groupsflin the manner illustrated in Flowsheet C.

Certain of the requisite 3-(a-hydroxyalkyl)-4,7-*indoloquinones may also be obtained in accordance with the following reaction scheme: A

FLOWSHEET F O 0 II I l CH2CR2 RzNHi I R1 0 R1 N R2 I R2 XLIX I L OH OH O l H I II R2 R1-C Rr-C ll l R1 N R2 R1 N R: R1 N R:

l I R; R2 R2 LIII LII LI on, on, I Il a R R C=O I I R1 1? R2 R1 N R2 R2 I H LIV LV I lie R CHOH I I I I) It,

LXVII Wherein R and R are hydrogen or lower alkyl, R is lower alkyl and R is lower alkanoyl. Thus, reaction of an appropriate alkylamine (I) with a triketone of type (XLIX) is productive of a 4-oxo-4,5,6,7-tetrahydroindole (L). Base-catalyzed acylation of the 4-oxotetrahydroindole (L) furnishes the corresponding -formy1 or 5- acyl-4-oxo-tetrahydroindole (LI), shown in Flowsheet F in one of the two possible enolic forms. Dehydrogenation of (LI), preferably on treatment with 2,3-dichloro-5,6-dicyanobenzoquinone, affords the 5-acyl-4-hydroxyindoles (LII), catalytic hydrogenation of which, preferably in the presence of palladium-on-carbon catalyst, then furnishes the 5-alkyl-4-hydroxyindo1e (LIII). After esterifying (for example, with acetic anhydride) the 4-hydroxy group in (LIII) to give (LIV), the 3-formyl or 3-acy1 group can be introduced. For example, on treatment of (LIV) with phosphorous oxychloride and dimethylformamide the 3-formyl derivative is obtained. The 3-formylor 3-acyl-4-alkanoyloxyindoles (LV) can be converted to the corresponding 4-ols (LVI) on base treatment and the latter compounds may be oxidized to the paraquinone (LVII), preferably by treatment with potassium dinitrosodisulfonate. The quinone aldehydes (LVII) then may be converted to the 5-alkyl-3-(a-hydroxyalkyl)indoloquinones (LXVII) on reduction with a metal hydride, preferably sodium borohydride, and reoxidation of the intermediate hydroquinone, preferably with acidic ferric chloride.

Certain of the requisite 3-(m-hydroxyalkyl)-4,7-indolo quinones may also be obtained in accordance with the following reaction scheme:

FLOWSHEET G O H II -OHz-C-R2 RzNHz Rr- 0 R1 N -R2 XLIX I L i OH I I RI Y N R: R1 N R: I I 0 R1 R2 LXII LVIII Illa R C=O R1- 1TI R2 LVI 0 II Illa 1121 o=0 R1 N [R2 II I O R:

LVII

ORB

N I I 0R5 R: LXIV LIX Ra Rs I I Rr- N R! I I ORa R2 LXV O I Ilia C=O I II I Rl R3 LXII I CHOH R1 N R:

LXVI

wherein R and R are hydrogen or lower alkyl, R is lower alkyl and R is lower alkanoyl. Treatment of the 4- oxotetrahydroxyindoles (L) with a dehydrogenating agent such as palladium in boiling curnene furnish the 4-hydroxyindoles (LVIII), which are converted into the 4-acyloxyindoles (LIX) on treatment with an alkanoyl anhydride. These acyloxyindoles (LIX) may then be converted into their 3-formy1 or 3-acy1 derivatives (LX) by any of several methods known to those skilled in the art. For example, on reaction with phosphorus oxychloride and dimethylformamide the 3-formyl derivative is obtained. After removal of the O-acyl group by treatment with base, the resulting 4-hydroxy-3-formyl or 3- acylindoles (LXI) may be treated with an oxidizing agent, for example, Fremys salt, to give the corresponding 3- substituted-4,7-indoloquinones (LXII). In the manner I described previously, treatment of the 3-acy1-4,7-indoloquinones (LXII) with a reducing agent such as sodium borohydride followed by oxidation of the intermediate hydroquin-one with a reagent such as ferric chloride, produces the 3-(u-hydroxyalkyl)-4,7-indoloquinone (LXVI).

The 3-formyl or 3-acyl indoloquinones (LXII) may also be prepared from the 4-hydroxyindole (LVIII) by an alternate pathway as follows. Oxidation of (LVIII) with Fremys salt affords the para-quinone (LXIII) which on reductive alkanoylation, for example on treatment with zinc, acetic anhydride and pyridine, gives the 4,7- bisalkanoyloxy derivative (LXIV). As described previously, the latter compounds (LXIV) may be converted to the 3-formyl or 3-acyl derivatives (LXV), which on basic hydrolysis to the intermediate 4,7diol corresponding to (LXV) and oxidation, for example, with acidic ferric chloride gives the aforementioned 3-acyl or 3- formyl indoloquinones (LXII).

Certain of the requisite 3-(a-hydroxyalkyl)-4,7-indoloquinones may also be obtained in accordance with the reaction scheme of Flowsheet H.

FLOWSHEETH 1110 II Ru 0:0 X :0 r n It l t It LXII LXVIII LXXVIII 0 II B0 II Re 5 I H0 =0 X o=o 1H t 1| 1 IL X R, HO \N/ B1 A it, A it,

LXX LXXI I lie l 11 0 ll I l X \/\N/ R2 R \/\NLRI t, t t,

LXXII LXXIII 0 0 A Illa ll Illa 12. 0: WEE-0H Xm:o11o11 X R! RsQ- RI Y I Y I LXXIV LXXv Ilia II R0 :orroH n-fijlnon \N/ R: R5O-\)\N/ R:

I n l LXXVI LXXVII ll Illa R2 I 0 Ba LXII 19 I 20 I I I l a I Ilia HO C=O I C=O H0 I I Y O R: O R: LXXX LXXXI LXXXII Ilia R50 I I CHOH H N R: I O R:

LXXVI wherein R and R are lower alkyl, R is hydrogen or lower alkyl and X is halogen.

Thus, treatment of the 3-formyl or 3-acyl 4,7'indoloquinone, unsubstituted at positions 5 and 6, (LXII), with halogen, preferably bromine or chlorine, gives the 5,6-dihaloquinone (LXVIII), which, in the aforesaid manner, on reduction and reoxidation of the intermediate hydroquinone furnishes the 5,6-dihalo-3 (a-hydroxyalkyl))-4,7-indoloquinones (LXIX). Further, treatment of the dihaloquinone intermediate -(LXVIII) with base, e.g. sodium hydroxide, affords both the 5-hydroxy-6- haloquinone (LXX) and the 6-hydroxy-5-haloquinone (LXXI). Treatment of (LXX) and (LXXI) with an alkylating agent gives the corresponding alkoxy-haloquinones (LXXII) and (LXXIII). Subsequent treatment of (LXXII) and (LXXIII) in the aforesaid manner with sodium borohydride and reoxidation of the intermediate hydroquinone with acidic ferric chloride furnishes the corresponding 5/6 alkoxy-5/6-halo-3-(a-hydroxyalkyD- 4,7-quinones (LXXIV) and (LXXV), respectively as well as the 6-unsubstituted-5-alkoxyindoloquinone carbi- LXXXIII H m CHOH Rs0k N [R2 0 I I:

LXXVII nol (LXXVI) and the S-unsubstituted-6-alkoxy-indoloquinone carbinol (LXXVII) respectively.

The 5- or 6-unsubstituted indoloquinones (LXXVI) and (LXXVII) may be obtained in an alternative manner as follows. Treatment of the 5-6-unsubstituted indoloquinone (LXII) with a mercaptan such as ptoluenethiol furnishes the S-toluenethioquinone (LXXV III) FLOWSHEET I O O I Ilia I I' l: HO C=O X C=O X CHOH I I I II I I I R1 I 17 R2 R1 R: R1 1TI R2 I 0 R1 0 R1 0 R1 LXXVIII LXXIX LXXX I R I R I o a Re I A I I R 0 C=O RsS C=O RaS CHOH I I II II II I I I Br I N R1 R1 Y I? R: R1 ITI R;

I 0 1 0 R1 0 R1 LXXXI 21 wherein R and R are hydrogen or lower alkyl, R and R are alkyl and X is halogen.

Thus, treatment of the 3-acylor 3-formyl-5-hydroxyindoloquinones (LXXVIII) with an appropriate halo- 22 Examples 2-6 By the procedure described in Example 1 the compounds of Table HI are obtained.

TABLE III- NHR:

R2C=CHCOOCH5 Starting Materials Product Exlarmple B.p., 0. (pressure) Ester Amine R R2 2 Ethyl acetoacetate Propylamine. C3111 CH3 110l19.5(14mm.). 3 do -Propyla mmefl (CHmCH CH3 106106.5 (11mm). 4 do Buty1am1ne ClHg CH3 129.513l.0(14m m.). 5 do Ethanlaine.. CHZOHZOH CH Decomposes. 6 Ethylpropiouylacetate Ethylamine..." Cal-I CzHs 118121(14mm.).

genating agent gives the S-haloquinones (LXXIX). For example, treatment with a solution of phosphorous oxychloride in dimethylformamide afiords a 5-chloro derivative. Subsequent reduction in the aforesaid manner with sodium borohydride and reoxidation of the intermediate hydroquinones with ferric chloride furnishes the S-halo- 3- a-hydroxyalkyl) -4,7-indoloquinones (LXXX) Treatment of 3-acylor 3-forrnyl-5-alkoxy-4,7-indoloquinones (LXXXI) with an alkyl mercaptan in the presence of an acidic catalyst, e.g., hydrochloric acid, affords the S-alkylthioquinones (LXXXII), which, as previously described, may be converted to the requisite S-alkylthio- 3-(a-hydroxyalkyl)-4,7-indoloquinones (LXXXIII) by reduction and subsequent reoxidation of the inter-mediate hydroquinone- The invention will be described in greater detail in conjuntion with the following specific examples.

Example l.--Prep|arati0n of ethyl ,B-ethylaminocrotonate With mechanical stirring a stream of ethylamine is introduced into 98.5 g. (100 ml.) of ethyl acetoacetate Example 7.Preparati0n of ethyl l-ethyl-S-hydroxy- 2,6-dimethyl-3-ind0lecarb0xylate A solution of 122 g. (0.0855 mole) of ethyl fi-ethylaminocrotonate (Example 1) in ml. of acetone is thoroughly swept with nitrogen and treated with 10.9 g. (0.895 mole) of toluquinone. The deep red solution is heated on the steam-bath for 2 hours, cooled in an icebath and filtered to give a dark solid. This material is Washed with cold acetone and dried to give 4.45 g. of gray crystals. The combined filtrate and washings are concentrated to about 50 ml. volume and placed in the refrigerator for 16 hours. The solid is collected by filtration and Washed with boiling light petroleum to give an additional 3.90 g. of crystals. A sample is recrystallized from dilute ethanol containing a trace of sodium hydrosulfite to give oil-white crystals, rn.p. 196198 C.

Examples 8-14 In the manner described in Example 7 the compounds of Table IV are prepared.

TABLE IV HO- O O 0 0 11 Product Example No. Starting Materials M.P., C.

I R1 R2 R3 Ethyl fl-methylaminocrotonate Toluquinone CH3 CH3 CH3 222-225 Product of Example 2 do CH3 C3I-I1 CHa 193. 5-195. 0 Product of Example 3 (CHmCH CH3 202-203 Product of Example 4 0 11; CH; 176177 Product of Example 5. CHZCH OH CH3 196. 0-197. 5

13 Product of Example 6. do CzHs CzH5 164-16 14 Product of Example 1..- Ethylbenzoquinone C 11 CH3 207-208 B All products are recrystallized from acetone-hexane.

b S. A. Glickman and A. C. Cope, J. Am. Chem. Soc. 67, 1019 (1945).

Clemmensen, Ber., 47, 56 (1914).

Example 15.Preparalion 0f I-eIhyI-S-hydroxy- 2,6-dimethylind0le A mechanically stirred mixture of 50.0 g. of ethyl 1- ethyl-S-hydroxy-2,6-dimethyl-3-indolecarboxylate (Example 7) and 500 ml. of 20% hydrochloric acid solution is heated at reflux temperature for 2 hours. The acid solution is diluted with 500 ml. of Water, saturated with sodium chloride and extracted well with ethyl acetate. The extracts are dried over magnesium sulfate and evaporated. The residue crystallizes from methylene chloridepetroleum ether (B.P. 30-60") to give 26.0 g. of crystals, M.P. 1l3117 C. An additional 4.8 g. of crystals is obtained by concentration of the mother liquor. This material also has a crystalline modification that melts at 9092 C. Both forms have identical infrared spectra in carbon tetrachloride solution.

Examples 16-22 In the manner described in Example 15 the compounds of Table V are obtained.

Example 32.Preparalion of J-(B-methanesulfonyloxyethyl)--methoxy-2,6-dimethylind0le To an ice-chilled, magnetic-ally stirred solution of 12.7 g. of 1-(fl-thydroxyethyl)-5 methoxy 2,6-dimethylindole (Example 20) in 100 ml. of pyridine is added dropwise ml. of met-h'anesulfonyl chloride. The resulting solution is kept at 0-5 C. for hours; water is then added, and the mixture is extracted with methylene chloride. The combined extracts are Washed with saline, dried over magnesium sulfate and evaporated. The residue is recrystallized from methylene ohloride-petroleurn ether (B.P. -60) to give crystals, M.P. 118-120" C. dec.

All products are recrystallized from methylene chloride-petroleum ether (b.p. 3060 0.).

Example 23.Preparation of 1-ethyl-5-meth0xy-2,6- dimethylindole To a magnetically stirred solution of 49.1 g. of l-ethyl- 5-hydroxy-2,6-dirnethylindole (Example 15) in 300 ml. of

ethyl alcohol and 600 ml. of 2 N sodium hydroxide solu- 4 tion is added dropwvise over 90 min. at reflux temperature under nitrogen 100 g. (74 ml.) of methyl sulfate. The resulting mixture is heated at reflux temperature for an additional minutes and then extracted with ethyl acetate. The extract is Washed with saline, dried over magnesium sulfate and evaporated. The residual brown oil is dissolved in benzene and passed through a magnesia-silica gel column (1.0 x 12.5 -in.), benzene being used as the elutin-g solvent and 250 ml. fractions being collected. Fraction 1 contains 46.9 g. of amber oil and fraction 2 contains 1.0 g. These fractions crystallize on standing. A sample of this material is recrystallized from hexane to give white crystals, M.P. 5 657 C.

Examples 24-31 By the procedure given in Example 23 the compounds of Table VI are obtained.

Example 33.Preparation 0f 2,5-dimethyl-4- nitroanisole A well stirred suspension of 16.7 g. (0.1 mole) of 2,5- dimethyl-4-nitrophentol (R. L. Datta and P. S. Varrna, J. Am. Chem. Soc., 41, 2042 (19-19)) in 50 ml. of water at 40-45" C. is treated alternately and in portions With a solution of 7.0 g. of sodium hydroxide in 18 ml. of Water and 12 ml. of methyl sulfate. After 2 hours the mixture is filtered, and the solid is recrystallized from dilute methanol to give 14.5 g. yield) of needles, M.P. 92 C.

Example 34.-Preparation of S-meth0xy-4-methyl-2-nitr0- phenylpyruvic acid Ethanol (6.25 ml.) is added to a mechanically stirred slurry of 2.15 g. (0.055 g.-atoms) of potassium in benzene. After all of the potassium reacts, the solvents are removed by distillation, benzene (50 ml.) is added and removed in the same manner. The cooled residue is slurried in ml. of ether and treated With 7.3 g. (0.05 mole, 6.75 ml.) of ethyl oxalate. To the resulting solution is added a solution of 9.05 g. (0.05 mole) of 2,5-dimethyl-4-nitro- TABLE VI R1- \N R3 Product Example No. Starting Material State R1 R2 R3 24 5-hydroxy-2,G-dimethylindole OH; H CH3 Solid, M.P. 94-96 O. 25 Product of Example 16 CH3 CH3 CH Solid, M.P. 7577 C, 26 Product of Example 17 CH CaH1 CH Oil. 27 Product of Example 18 CH5 (CHmCH CH3 Do. 28-.- Product of Example 19.- CH3 CH9 CH3 Do. 29-.. Product of Example 20 CH; CHzCHzOH CH3 Solid, M.P. 78-80 C. 30 Product of Example 21 CH CzHs CzHs Oil. 31 Product of Example 22 CzHs CZH CH Do.

RJZS. Beer, et al., J. Chem. Soc., 2029 (1951).

25 an-isole (Example 33) in 150 ml. of ether. A 'red solid separates immediately and the mixture is mechanically stirred at room temperature for 18 hours and then at reflux temperature for 4 hours. The mixture is filtered, and the solid is washed with ether. The residue is dissolved in water and the solution is heated on the stea'm brath for 30 minutes. The solution is cooled and extracted with ether. The aqueous solution is acidified with hydrochloric acid and filtered to give 6.123 g. of crystals, M.P. 167-170 C.

Example 35.Preparatin of -methoxy-6-methyl-2- indolecarboxylic acid A solution of 42.0 g. (0.166 mole) of 5-methoxy-4- methyl-2-nitrophenylpyruvic acid (Example 34) in 230 ml. of 17% ammonium hydroxide and 115 ml. of water is treated with a hot solution of 300 g. of cferrous sul fate heptahydrate in 340 ml. of water. The mixture is mechanically stirred at steam-bath temperature for 1 hour and then allowed to cool to room temperature and filtered. The residue is Washed with dilute ammonium hydroxide until a test portion becomes only milky on acidification. The combined filtrate and washings are acidified with hydrochloric acid and the solid which separates is collected by filtration. The moist solid is recrystallized from dilute acetic acid to give 19.0 g. (56% yield) of light brown solid, M.P. 240-242" C. (gas evolution).

Example 36.Preparation of methyl S-methoxy-lS-methyl- Z-indolecarboxylate A solution of 4.00 g. of S-methoxy-6-methyl 2-indolecanboxyl ic acid (Example 35) in 100ml. of methano-lic hydrogen chloride is heated at reflux temperature for 16 hours. The solvent is evaporated, and the residue is recrystallized from dilute methanol to give white needles, M.P. 147-149 C.

Example 37.--Preparati0n of methyl 1-ethyl-5-meth0xy-6- methyl-Z-indolecarboxylate To a mechanically stirred solution of 15.40 g. of methyl 5-rnethoxy-6-methyl-2-indolecarboxylate (Example 36) in 5 00 ml. of benzene is added 3.55 g. of a 50.7% suspension of sodium hydride in mineral oil. Gas evolution is noted almost immediately, and a gray flocculent solid separates. The mixture is heated at reflux temperature for 45 minutes, and then 25 ml. of ethyl sulfate is added over minutes. The resulting mixture is heated at reflux temperature for 4 hours and filtered while hot. The solvent is removed from the filtrate by evaporation, and the excess ethyl sulfate is removed at oil-pump pressure. The residue is agitated with 250 ml. of boiling hexane and filtered. The filtrate is concentrated to about one half its original volume and chilled to give White needles, M.P. 10 1- 102 C.

Example 38.--Preparati0n of 1-etIzyl-2-hydr0xymethyl-5- meth0xy-6-methylindole A magnetically stirred mixture of 7.00 g. of methyl 1 ethyl-S-methoxy-6-methyl-2-indolecarboxylate (Example 37) and 2.17 g. of lithium aluminum hydride in 470 ml. of ether is heated at reflux temperature for 2.5 hours; stirring is continued for an additional 16 hours. Ethyl acetate (60 ml.) is added cautiously, and then 60 ml. of water is added. The bulk of the ethereal phase is decanted from the aqueous phase which is then diluted with Water and extracted With ethyl acetate. The combined organic solutions are Washed with saline, dried over sodium sulfate and evaporated. The residue is recrystallized from ether-petroleum ether (B.P. -60") to give white needles, M.P. 103-106" C.

Example 39.Preparati0n of Z-acetoxymethyl-I-ethyl-5- meth0xy-6-methylind0le A solution of 5.49 g. of 1-ethyl-2-hydroxymethyl-5- methoxy-o-methylindole (Example 38) and 7 ml. of acetic anhydride in 60 ml. of pyrid-ine is kept at room temperature for 17 hours. The solution is diluted with water to a volume of about 400 ml. and chilled to give white needles, M.P. 9697 C.

Example 40.Preparati0n of 1-ethyl-5-methoxy-2,6-dimethyl-S-indolecarboxaldehyde To 200 ml. of magnetically-stirred, ice-chilled dimethylforrnamide is added dropwise at such a rate that the temperature remains at 05 C. 55 g. (32.8 ml.) of phosphorus oxychloride. The resulting solution is treated with a solution of 66.35 g. of 1-ethyl-5-methoxy-2,6-dimethylindole (Example 23) in 150 ml. of dimethylformamide at such a rate that the temperature does not exceed 5 C. The ice bath is removed and replaced by a warm waterbath, and the mixture is stirred at 40 C. for 1.25 hours. Cracked ice (200 ml.) is added and the mixture is transferred to a 3-1. round-bottom flask containing about 300 g. of cracked ice, 200 ml. of Water being used to aid in the transfer. A solution of 250 g. of sodium hydroxide in 650 ml. of water is added dropwise with mechanical stirring until about one-half of the solution has been added; the remainder of the solution is added rapidly. The resulting mixture is heated to the boiling point, diluted with water to a volume of about 2.5 l. and cooled. Filtration gives 70.5 g. of crystals, M.P. 134- 136 C.

Examples 41-50 By the procedure given in Example the compounds of Table VII are obtained.

TABLE VII CHsO CHO Product Example No. Starting Material M.P., 0.

R1 Ra a Product of Example 24---. CH H CH; 227. 0-228. 5 Product of Example 25 CH3 CH3 CH3 174-178 Product of Example 26 CH3 O3H7 CH3 117. 5-119. 5 Product of Example 27 CH; (CHmCH CH3 172-174 Product of Example 28 CH3 04H CH3 96-97 Product of Example 30"-- CH3 C2115 02115 95. 5-97. 0 Product of Example 31.... C211 C211 CH3 109-110 Product of Example 32 CH; CHzCHzO SOzCHa CH 1 187. 5-189. 0

. I] 49 Product of Example 39 CHa CrHs OHQO 0 CH 1225-1215 50 Product of Example 37 CH3 CzH C O 0 CH 178 5-180. 0

A mechanically stirred mixture of 12.9 g. of l-ethyl- 5-methoxy-2,6-dimethylindole (Example 23) and 10 g. of sodium acetate in 300 ml. of acetic anhydride is heated at reflux temperature for 6 hours. The reaction mixture is cooled, poured onto crushed ice and stirred for 3 hours. The reaction mixture is warmed on the steam-bath and then stirred for an additional 30 minutes and then extracted with methylene chloride. The extract is successively washed with water, saturated sodium bicarbonate solution and finally with water. The organic solution is dried over anhydrous sodium sulfate and taken to dryness to give 14 g. of an oil. A sample of the oil is distilled and the fraction boiling at 150-170 C./0.2 mm. Hg is crystallized from petroleum ether (B.P. 30-60") to give a white solid, M.P. 88-89 C.

Example 52.Preparati0n of 1-ethyl-5-hydr0xy-2,6- dimethyl-3-z'ndolecarboxaldehyde A mixture of 38.4 g. of 1-ethy1-5-methoxy-2,6-dimethyl- 3-indolecarboxaldehyde (Example 40) and 46.0 g. of aluminum chloride in 1 l. of xylene is mechanically stirred at reflux temperature for 5 hours. The cooled mixture is treated with cracked ice and digested to give 38.0 g. of pink solid, M.P. 246250 C. dec. A sample is recrystallized from acetone to give cream-colored crystals, M.P. 256-259 C. dec.

Example 53.Preparati0n of 3-acetyl-I-ethyl-5-hydroxy- 2,6-dimethylind0le A mixture of 12 g. of the crude 3-acetyl-1-ethyl-5- methoxy-2,6-dimethylindole (Example 51) and 13.1 g. of aluminum chloride in 450 ml. of xylene is mechanically stirred at reflux temperature for 5 hours. The cooled mixture is treated with cracked ice and digested to give 8.2 g. of a pink solid, M.P. 250255 C. A sample is recrystallized from acetone to give cream colored crystals, M.P. 262-265 C. dec.

Example 54.Preparati0n of ethyl 1-ethyl-2,6-dimethyl- 4,5-di0x0-3-indolecarboxylate To a mechanically stirred solution of 18.0 g. of potassium nitrosodisulfonate in 400 ml. of water and 200 ml. of M/ 6 potassium dihydrogen phosphate is added a solution of 2.47 g. of ethyl 1-ethyl-5-hydroxy-2,6-dimethyl-3 indolecarboxylate (Example 7) in 500 ml. of acetone. The resulting brown solution becomes purple in 5-10 min. and is allowed to stand at room temperature for 16 hours. The solution is diluted with water and extracted with methylene chloride. The combined extracts are dried over magnesium sulfate and taken to dryness. The residue crystallizes upon trituration with ether. This material is crystallized from acetone-petroleum ether (B.P. 60-70 C.) to give, in three crops, 1.545 g. of black crystals, M.P. 1l5118 C.

Example 55.Preparati0n of I-ethyl-2,6-dimethyl-4,5- di0x0-3-indolecarboxaldehyde To a mechanically stirred solution of 50.0 g. (0.187

mole) of potassium nitrosodisulfonate in 1440 ml. of M/ 6 potassium dihydrogen phosphate solution and 2510 ml. of water is added a solution of 18.75 g. (0.0864 mole) of 1 ethyl 5-hydroxy-2,6-dimethyl-3-indolecarboxaldehyde (Example 52) in 3950 ml. of hot acetone. Some solid separates, and an additional- 400 ml. of acetone is added. The initially blue solution turns brown on addi tion of the aldehyde and becomes purple within 5 minutes. Stirring is continued at room temperature for 1 hour. The reaction mixture is then concentrated under reduced pressure, 3200 ml. of distillate being collected. The concentrate is chilled and filtered. The residue is washed well with water and air-dried to give 16.05 g. of black needles, M.P. 205-208 C. A sample is re 2?: crystallized from acetone-hexane to give black needles, M.P. 214-216 C.

Example 5 6 .Preparation of 3-acetyl-1-ethyl-2,6- dimethyl-4,5-di0x0ind0le To a mechanically stirred solution of 2.05 g. of potassium nitrosodisulfonate in 153 ml. of M/ 6 potassium dihydrogen phosphate solution and 300 ml. of water is added a solution of 295 mg. of 3-a-cetyl-l-ethyl-S-hydroxy- 2,6-dimethylindole (Example 53) in 300 ml. of hot acetone. The initially blue solution turns brown on addition of the indole and becomes purple within 30 minutes. Stirring is continued at room temperature for 4 hours. The solution is diluted with an equal volume of water and extracted with methylene chloride. The combined extracts are washed with saline, dried over anhydrous sodium sulfate and concentrated to small volume and filtered. The filtrate is evaporated with concomittant addition of petroleum ether (3060 C.). Once crystallization begins, the mixture is cooled. Filtration gives 176 mg. of dark brown solid, M.P. 162-l65 C. A sample is recrystallized from methylene chloride-petroleum ether (30-60 C.) to give dark brown needles, M.P. 164-166" C.

Example 57.Preparati0n of ethyl 1-ethyl-4,5,7-trihydroxy-Z,6-dimethyl-3-ind0lecarb0xylate triacetate To a solution of 400 mg. of ethyl 1-ethyl-2,6-dimethyl-4,5-dioxo-3-indolecarboxylate (Example 54) in 6 ml. of acetic anhydride is added 0.125 ml. of boron trifluoride etherate; the purple solution immediately turns brown. It is kept at room temperature for 1 hour, and then poured onto cracked ice. After the excess acetic anhydride hydrolyzes, the mixture is extracted with methylene chloride. The extract is taken to dryness and the amorphous residue crystallizes with ether to give 450 mg. of crystals, M.P. -158 C. Two recrystallizations from acetone-petroleum ether (B.P. 30-60 C.) give White crystals, M.P. 157159 C.

Exdmple 58.-Preparation of I-ethyl-4,5,7-trihydr0xy- 2,6-dimethyl-3-ind0lecarboxaldehyde triacetate To a magnetically stirred mixture of 10.00 g. (43.3 mmoles) of 1-ethyl-2,6-dimethyl-4,5-dioxo-3-indolecarbox-aldehyde (Example 55) in 150 ml. of acetic anhydride is added 2 ml. of boron trifluoride etherate. All solid quickly dissolves and the purple mixture becomes brown and is stirred at room temperature for 1 hour. Cracked ice is added, and the mixture is stirred at room temperature until the excess acetic anhydride hydrolyzes. The resulting solid is collected by filtration and washed with water to give 12:5 g. of grey solid, M.P. 173-l80 C. A sample is recrystallized from acetone-hexane to give white crystals, M.P. 194-195 C.

Example 59.Preparati0n of 4,5,7-triacetoxy-3-acetyl- 1-ethyl-2,6-dimethylind0le enol acetate To a magnetically stirred mixture of 657 mg. of 3-acetyl-1-ethyl-2,6-dimethyl-4,S-dioxoindole (Example 56) in 8 ml. of acetic anhydride is added 0.2 ml. of boron trifluoride etherate. The solid dissolves and the purple mixture becomes dark brown and is stirred at room temperature for several hours. Cracked ice is added, and the mixture is stirred until the excess acetic anhydride hydrolyzes. The resulting solid is collected by filtration and washed with water to give 888 mg. of brown solid. The crude material is triturated with cold methanol to give 467 mg. of a yellow solid, M.P. 195200 C.

Example 60.Preparati0n of 1-ethyl-5-hydr0xy-2,6-

dimethyl-4,7-di0x0-3-ind0lecarb0xylic acid A mixture of 2.55 g. of ethyl 1-ethyl-4,5,7-trihydroxy- 2,6-dimethyl-3-indolecarboxylate triacetate (Example 57) in 100 ml. of water and 20 ml. of 25% sodium hydroxide solution is heated at reflux temperature in an atmosphere of nitrogen with magnetic stirring for 30 minutes. The undissolved solid is collected by filtration to give 0.489 g. of solid. The filtrate is treated with a stream of air for 30minutes. This purple solution is acidified by dropwise addition of concentrated hydrochloric acid solution, and the resulting solution is extracted with methylene chloride. The extract is taken to dryness and the residue is crystallized from the methylene chloride-petroleum ether (B.P. 60-70 C.) to give 1.010 g.-of red needles, M.P. 220-223 C.

Example 61.--Preparation f I-ethyl--hydr0xy-2,6-dimethyl-4,7-di0x0-3-ind0lecarb0xaldehyde A mechanically stirred mixture of 30.10 g. (0.080 mole) of 1-ethyl-4,5,7-trihydroxy-2,6-dimethyl-3-indolc carboxaldehyde triacetate (Example 58) in500 ml. of water and 125 ml. of 25% sodium hydroxide solution is heated at reflux temperature under nitrogen for 1 hour. All solid dissolves and the brown solution is quickly filtered. A stream of air is passed through the filtrate for 35 minutes. The resulting purple solution is acidified by addition of 37% hydrochloric acid solution. Once acid, a red solid separates from the solution. It is extracted into methylene chloride and the extracts are dried over magnesium sulfate and evaporated with concomittant addition of petroleum ether (B.P. 30-60" C.). Once crystallization begins, the mixture is placed in the refrigerator. Filtration gives 13.6 g. of rose needles, M.P. 213-215 C. Concentration of the filtrate gives an additional 2.9 g. of this quinone.

Example 62.Preparati0n of 3-acetyl-1-ethyl-5-hydr0xy- 2,6-dimethyl-4,7-dioxoind0le A magnetically stirred mixture of 53 mg. of 4,5,7-triacetoxy-3-acetyl-1-ethyl-2,6-dimethyl indole enol acetate (Example 59) in 3 ml. of water and 0.4 ml. of 25% sodium hydroxide solution is heated at reflux temperature, under nitrogen, until solution occurs. The reaction mixture is filtered and a stream of air is passed through the filtrate for 40 minutes. The resulting purple solution is acidified by addition or 37% hydrochloric acid solution. The acid solution is extracted with methylene chloride and the extracts washed with water. The organic solution is dried over anhydrous sodium sulfate and taken to dryness. The residue is recrystallized from methylene chloride-petroleum ether (30-60" C.) to give 11 mg. red crystals, M.P. 172175 C.

Example 63.Preparati0n of methyl 1-ethyl-5-meth0xydimlethyl-4,7-diox0-3-ind0lecarb0xylate A magnetically stirred mixture of 681 mg. of l-ethyl- Example 64.Preparation of 1-ethyl-5-meth0xy-2,6-dimethyl-4,7-di0x0-3-ind0lecarb0xalaehyde A mechanically stirred mixture of 21.9 g. (0.089 mole) of 1-ethyl-5-.hydroxy-2,6-dimthyl-4,7 dioxo-3-indolecarboxaldehyde (Example 6.1), 100 g. of potassium carbon'ate and 6.75 g. of dimethyl sulfate in 1 l. of acetone is heated at reflux temperature for 1 hour, whereafter stirring is continued at room temperature for 3 hours.

30 The mixture is filtered and the residue is washed well with acetone. The combined filtrate and washings are evaporate-d, the excess dimethyl sulfate being removed at oil-pump pressure. The residue is dissolved in 200 ml. of acetone and treated, with magnetic stirring, with about 800 ml. of water. Stirring is continued for 30 minutes, and the resulting mixture is chilled and filtered to furnish 18.9 g. of needles, M.P. 124-127 C. For purification this material is dissolved in methylene chloride and passed through a magnesia-silica gel column, methylene chloride being used as a wash solvent. The eluate is essentially colorless "after 2.5 l. is collected. The solvent is removed and the residue is crystallized from methylene chloride-petroleum ether ('B.P. 3060 C.) to give 15.08 g. of red needles, M.P. 133135 C.

Example 65 .Preparation of 5-eth0xy-1-ethyl-2,6-dimethyl-4,7-di0x0-3-ind0lecarboxaldehyde 1-ethyl-5-hydroxy-2,6 di-methyl-4,7-dioxo-3-indolecarboxaldehyde (1.0 g.) (Example 61) in tetraethoxymethane is heated at reflux temperature for 3 hours. The mixture is distilled almost to dryness. Methanol (4 ml.) is added and red-orange crystals precipitate. These are collected and washed with methanol to gixe orange-red needles, M.P. 117-L19 C.

Example 66.-Preparati0n of S-acetyl-I-ethyl-5-meth0xy- 2,6-dimethyl-4,7-dioxoind0le A magnetically stirred mixture of 163 mg. of B-acetyl- 1-ethyl-5-hydroxy-2,6-d imethyl-4,7-dioxoindole (Example 62), 1.6 g. of potassium carbonate and 4 ml. of di-methyl sulfate in 93 ml. of acetone is heated at reflux temperature for 45 minutes and then stirred at room temperature for 2 hours. The mixture is filtered and the residue washed with acetone. The combined filtrate and washings are concentrated, most of the excess alkylating agent being removed on the steam-bath at reduced pressure. The residue is dissolved in a minimum amount of benzene and placed on a magnesia-silica gel column, ether being used as a wash solvent. The combined washings are concentrated to dryness and the residue is recrystallized from methylene chloride-petroleum ether (3060 C.) to give 91 mg. of orange crystals, M.P. l26-127 C.

Example 67 .Preparation of 1-ethyl-3-hydr0xymethyl-5- meth0xy-2,2,6-dimethyl-4,7-diox0ind0le To a magnetically stirred solution of 334 mg. (1.15 moles) of methyl 1-ethy1-5-methoxy-2,6-dimethyl-4,7-dioxo-3-indolecarboxylate (Example 63) in 25 m1. of tetrahydrofuran 'is added 197 mg. (5.2 mmoles) of lithium aluminum hydride. The resulting colorless mixture is heated at reflux temperature for 1 hour. Ethereal ferric chloride (1.0 g. in 20 ml.) is slowly added followed by the cautious addition of ethyl acetate and then water. The resulting mixture is destributed between ethyl acetate and water. The organic solution is washed with saline, dried over magnesium sulfate and taken to dryness to give 314 mg. of oil. This material is subjected to chromatography on diatomaceous earth using a n-heptane: ethyl acetate:methanol:water (90:10:1724) system. Removal of the solvent from hold back volume 3.1-4.2 gives red crystals having melting point 87 C.

Example 68.Preparati0n 0f 1-ethyl-3-hydroxymethyl-5- meth0xy-2,6-dimethyl-4,7-di0xoind0le A magnetically stirred solution of 500 mg. (1.38 mmoles) of 1-ethyl-5-methoxy 2,6-dimethyl-4,7-dioxo-3- 31 indolecarboxaldehyde (Example 64) in 150 ml. of methanol is swept with a stream of nitrogen, heated to reflux temperature and treated with 500 mg. of sodium borohydride. Boiling is continued for 2-3 minutes, and the solution is then stirred under nitrogen at room temperature for 1 hour. Acetone (5 ml.) is added followed by 5 ml. of a 1 N ferric chloride in 0.1 N hydrochloric acid solution. The resulting mixture is distributed between methylene chloride and water. The aqueous layer is extracted an additional two times with methylene chloride. The combined extracts are Washed with saline, dried over magnesium sulfate and evaporated. The residue crystallizes from methylene chloride-petroleum ether (B.P. 3060 C.) to give 377 mg. of red needles, M.P. 85.5-86.5 C.

Example 69.Preparation of S-ethoxy-I-ethyl-3-hydr0xymethyl-2,6-dimelhyl-4,7-dixoind0le In the manner described in Example 68 treatment of -ethoxy-1-ethyl-2,6-dimethyl-4,7 dioxo-3-indolecarb-oxaldehyde (Example 65) with sodium borohydride in methanol and oxidation of the resulting hydroquinone with ferric chloride is productive of orange needles, M.P. 65-70 C.

Example 7 0.-Preparati0n 0 1-ethyl-3-(1-hydr0xyethyl) 5-meth0xy-2,6-dimethyl-4,7-diox0ind0le A magnetically stirred solution of 100 mg. of 3-acetyl-1- ethyl 5-methoxy-2,6-dimethyl-4,7-dioxoindole (Example 66) in ml. of methanol is heated to reflux and 100mg. of sodium borohydride is added under nitrogen. The resulting mixture is heated for 1 to 2 minutes and then allowed to stir for 1 hour at room temperature. To the solution is added 1 ml. of acetone, and after 5 minutes, followed by 1 ml. of 1 N ferric chloride in 1 N hydrochloric acid solution. The resulting mixture is distributed between methylene chloride and water. The organic solution is washed with saline, dried over anhydrous sodium sulfate and taken to dryness to give a reddish oil.

Example 71.Preparati0n of 5-m thoxy-6-methylindole S-methoxy-6-methyl-2-indolecarboxylic acid (Example 35) (3.61 g., 17.6 mmoles) is heated at 260270 C. until the melt becomes quiescent and then taken to and held briefly at 300 C. The cooled material is dissolved in ether, and this solution is Washed with sodium carbonate solution, treated with activated carbon, dried over magnesium sulfate and taken to dryness. The solid is recrystallized from ether-petroleum ether to give 2.12 g. of crystals, M.P. 119120 C.

Example 72.Preparati0n of 5-metl10xy-6-methyl- 3-z'nd0lecarb0xaldehyde To 3.5 ml. of dimethylformamide is added with magnetic stirring and ice cooling 1.69 g. (11 mmoles, 1 ml.) of phosphorus oxychloride. To this solution is then added dropwise a solution of 1.61 g. (10 mmoles) of 5- methoxy-6-methylindole (Example 71) in 8 ml. of dimethylformamide. The temperature of the reaction is kept below 10 C. during the addition which requires 20 minutes. A solid separates minutes after the start of the addition. Upon completion of the addition, the ice bath is removed and replaced by a warm water bath. The paste is kept at 3035 C. with magnetic stirring for 45 minutes. Crushed ice is added to the mixture which is then treated with a solution of 4.5 g. of sodium hydroxide in .20 111. of water. The mixture is brought to boiling and then chilled in an ice bath to give 1.74 g. of tan solid, M.P. 192195 C.

Example 73.--Preparati0n of 1-ethyl-5-meth0xy-6- methyl-3-ind0lecarb0xala'ehyde A mixture of 1.75 g. (9.2 mmoles) of 5-methoxy-6- methyl-3-indolecarboxaldehyde (Example 72) and 30 ml. of 40% potassium hydroxide solution is heated with mechanical stirring on the steam bath. When the mixture becomes hot, all solid dissolves and 10.0 g. (65 mmoles, 8.5 m1.) of ethyl sulfate is added in five equal portions over 1 hour. The solution is allowed to cool, Whereon crystals separate from the aqueous solution. The mixture is extracted with ethyl acetate, and the extract is washed with saline, dried over magnesium sulfate and evaporated. The residue crystallizes from etherpetroleum ether (B.P. 30-60" C.) to give 1.287 g. of crystals, M.P. 92-94 C.

Example 74 .Preparation of 1-ethyl-5-methoxy-6- methyl-4-nitro-3-indolecarboxaldehyde To an ice chilled, magnetically stirred solution of 1.085 g. (5.0 mmoles) of 1-ethyl-5-methoxy-6-methyl-3-indolecarboxaldehyde (Example 73) in 12 ml. of concentrated sulfuric acid is added dropwise over 30 minutes a solution of 0.425 g. (5.0 mmoles) of sodium nitrate in 7 ml. of concentrated sulfuric acid. The resulting solution is stirred for an additional 45 minutes and then poured onto a cracked ice-water mixture. The solid is extracted into methylene chloride and the extract is washed to neutrality with saline, dried with magnesium sulfate and evaporated. The residue is crystallized from acetone-hexane to give 525 mg. of light yellow solid, M.P. 152 C.

Example 75.Preparati0n of 1-ethyl-5-methoxy-2,6- dim thyl-4-nitro-3-ind0lecarb0xaldehyde In the manner described in Example 74 treatment of 1 ethyl-5-methoxy-2,6-dimethyl-3-indolecarboxa.ldehyde (Example 40) with. sodium nitrate in sulfuric acid produces orange crystals, M.P. 157 C.

Example 76.Preparalion of methyl I-ethyl-3-formyl-5- meth0xy-6-methyl-4-nitr0-2-ind0lecarb0xylate Example 77.Preparation of methyl 1-ethyl-3-f0rmyl-6- methyl-4,5-di0x0-2-indolecarboxy'late The filtrate obtained from Example 76 is extracted with methylene chloride. The combined extracts are washed with saline, dried over sodium sulfate and evaporated. The residue is recrystallized from acetone-hexane to give red needles, M.P. 207-210" C.

Examples 78-86 In the manner described in Example 76 the compounds of Table VIII are obtained.

TABLE VIII CHaO- CHO R1 [Hz Product Example N0. Starting Material M.P., C.

7 R1 R3 R3 Product of Example 41 CHa H CH; 280 Product of Example 42..-- CH3 CH3 CH 183-187 Product of Example 43. CH C 11 CH 136-138 Product of Example 44 CH; (CHQ CH CH Product of Example 45-"- CH3 04H CH3 127-128 Product of Example 46.--- H3 C 11 C H 151-154 Product of Example 47-..- C 11 C2115 CH; 181. 0-182. 5 Product of Example 48..-- CH CHzCHzOSO 0H; CH 181. 5-183. 0

(H 86 Product of Example 49 CH3 CzH5 CHgO C CH; 198-200 1 Crude.

Example 87.Preparati0n of 1-ethyl-3-f0rmyl-5- meth0xy-6-methyl-4-nitro-Z-indolecarboxylic acid Example 88.-Preparation 0f 1-ethyl-3-f0rmyl-5- m cthoxy-o-methyl-4-nitro-2-in'd0'lecarb0xamide To an ice-chilled, magnetically stirred solution of 2.154 g. of l-ethyl-3dormyl-S-methoxy-6-methyl-4-nitro- 2-indolecarboxy'lic acid (Example 87) and 1.14 ml. of triethylamine in ml. of N,-N-dirnethylrformamide is added dropwise 0.79 ml. of ethyl chlorocarbonate at such a rate that the temperature is maintained between 0- C. A solid separates. Almmonia gas is then 'passed into the reaction mixture for 10 minutes. The resulting mixture is diluted with water and cooled in an ice-bath to give a solid which is recrystallized from acetone to give white crystals, MJP. 252-254 C.

Example 89.Preparwti0n of I-(fl-fluoroethyl) -5-methoxy-Z,6-dimethyl-4-nitr0-3-ind0lecarb0xaldehyde A mixture or" 5.00 g. of 1- (fi-methanesul fionyloxyethyl)- 5 methoxy 2,6 dimethyl 4 nitr-o 3 indolecarboxaldehyde (Example 85) and S .00 g. of \powdered potassium fluoride dihydrate in 160 ml. of methanol is placed in a stainless steel bomb and heated at 150 C. for 18 hours. The bomb is cooled, and its contents are distributed between methylene chloride and Water. The organic layer is washed with saline, dried over magnesium sulfate and evaporated. The residue is recrystallized from acetonepetroleum ether (B.P. 60-70 C.) to give yellow crystals, M.P. 175-178 C.

Example .90.Preparati0n of I-(B-acetoxyethyl)-5-meth- 0,xy-2,6-dimethyl-4-nitro-3-ind0lecarboxaldehyde A mixture of 500 mgof l-(fl-metha-nesulfonyloxyethyl) 5 methoxy 2,6 dimethyl 4 nitro 3 indolecarboxaldehy-de (Example and 1.00 g. of

acetate in 25 ml. ofdimethylformamide isheated on the steam bath .for 15 hours. The mixture is diluted with water, and the precipitated solid is collected by filtration and recrystallized from acetone-petroleum ether (B.P. 30-60 C.) to give crystals, M.P. 179180 C.

Example 91.Preparati0n of 4-amin0-5-meth0xy-1,2,6- trimethyl-3-indolccarboxaldehyde A mechanically stirred solution of 13.15 g. of 5- methoxy-1,2,6-trimethyl-4-nitro-3 indolecarboxaldehyde (Example 79) in 875 ml. oi alcohol and 375 ml. or water is heated to steam-bath temperature. A solution of 134 g. of *ferrous sulfate hep'tahydrate in 1250 ml. of water is added, and the mixture is heated to boiling. At 30-60 second intervals 10 ml. of concentrated ammonium hydroxide solution is added until a total of m1. is added. The resulting mixture is heated for 15 minutes after the last addition and then filtered. The residual cake, is washed thoroughly with methylene chloride. The combined filtrate and washings are shaken well, and the organic layer is separated. The aqueous phase is extracted further with methylene chloride, and the combined organ- Examples 92-98 In the manner described in Example 91 the compounds of Table IX are obtained.

TABLE IX CHsO CHO Product Exlarmple Starting Material M.P., C.

Product of Example 75---. CH3 C211 CH3 117. 5-118. 5 Product of Example 83--.. CH C2H5 H; Product of Example 80.--. OH; C l-I CH3 128-129 Product of Example 82...- CH C4110 CH; 129. -131. 0 Product of Example 86.. CH C 11 CH OH 182. 0-182. 5

II 97 Product of Example 86.... CH; C2115 CHzO C CH 136-138 98 Product of Example 88 CH C2H CON H3 202-203 1 Oil.

Example 99.Preparation 0f 4-amin0-1-(B-methanesulfanyloxyethyl) -5-methoxy-2,6 dimethyl 3 indolecarboxaldehyde A mechanically stirred solution of 15.00 g. of l-(fimethanesul fonyloxyethyl) 5 methoxy 2,6 dimethyl- 4-nitro-3-indolecarboxaldehyde (Example 85) in 450 ml. of glacial acetic acid and 45 ml. ott water is heated to steam-hath temperature, and 20.00 g. of iron filings are added in thirteen approximately equal portions over 2 hours. An additional 45 ml. of water is added after 45 minutes, and the reaction is heated minutes after the last addition of iron filing-s. Water is added, and the mixture is extracted with methylene chloride. The combined extracts are washed with water, potassium carbonate solution and finally with water, dried over'magnesi-um sulfate and evaporated. The residue is recrystallized from methylene chloride-petroleum ether (B.P. 30- 60 C.) to give tan crystals, M.P. 133-135 C.

Examples 100-104 In the manner described in Example 99 the compounds chloride-petroleum ether to furnish tan crystals, M.P. 123124 C.

Examples 106-108 TABLE XI NHz CHaO- CHO CH CHa l CHzCHzX Example No. Nuclcophile Product X M.P., C.

of a. X r atin.

T ble a 6 0b a '"Acetone solvent.

TABLE X N H;

C a0 CHO Product I ExlaImple Starting Material M.P., C.

R1 R2 R3 100 Product of Example 78.... OH; H CH 101 Product of Example 81 CH; CH(CHa)2 CH 102. Product of Example 84.... 02115 2 5 CH 110. 5-112. 5 103 Product of Example 89-.-. CH3 CH CH F CH 139-141 l 104 Product of Example CH CHzCH O 0 CH3 CH3 178-180 1 Crude. 1 Oil.

Example 105.Preparation of 4-amino-1-(fi-azidoethyl)- 5-methoxy-Z,6-dimethyl-3-indolecarboxyaldehyde to give solid which is recrystallized from methylene 75 Example 109.Preparati0n of 4-amino-1-(fi-hydroxyethyl)-5-metlz0xy-2,6-dimethyl-3-ind0lecarb0xaldchyde A solution of 2.466 g. of 1-(,B-acetoxyethyl){4-amino- 70 5 methoxy 2,6 dimethyl 3 indolecarboxaldehyde (Example 104) in ml. of methanol containing 6 ml.. of 10% potassium carbonate solution is stirred at'room temperature under nitrogen for 1 hour. Approximatelyhalf the solvent is removed after acidification with 0.45

ml. of acetic acid. The concentrate is diluted with 200 37 ml. of water and chilled to give tan needles, M.P. 157- 159 C.

Example 1 10.Preparatin of -meth0xy-1,2,6-trimethyl- 4,7-di0x0 3-indolecarboxa ldehyde Y 7 38 Example 130.Preparati0n of methyl 4,5,7-triacet0xy-3- diacetoxymethyl-l-ethyl-6-methyl-Z-indolecarboxylate In the manner described in Example 57 treatment of methyl 1 ethyl-3-formyl-6-methyl-4,5-dioxo-2-indo1ecar- 5 box late (Exam le 77) with acetic anh dride and boron A solution of 5.38 g. of 4-amino-1,2,6-trimethyl-5- y p y o methoxy 3dindolecarboxaldehyde (Example 91) in 1 L trifiuonde etherate gives crystals, M.P. 139-149 C. of acetone is added to a magnetically stirred solution of Exam ple 131.-Preparatz0n of 1-cthyl-3-f0rmyl-5-hy- 25.0 g. of potass1um mtrosodrsulfonate (Fremys salt) m [4 d b in 800 ml. of Water and 400 ml. of M/ 6 potassium dihydroxy me y mm m Olecar Oxyhc drogen phosphate solution. Stirring is continued for 2 I h manner d ribed in Example 60 hydrolysis of hours, and the mixture is allowed to stand at room temh l 4 5,7 triacetoxy 3-diacetoxymethyl-1-ethyl-6- perature for hours, whcreafter it is diluted with water methypzdndolecarboxylate (Example 30. with Sodium and extractedwith methylene chloride. The combined hydroxide Solution and subsequent air Oxidation of the extracts are dried over magnesium sulfate and evaporated. 5 alkaline solution produces orange crystals, 1 1 The residue is dlssolved in methylene chloride and 1 3 chromatographed on magnesia-silica gel. The material eluted by methylene chloride is recrystallized from Example 132.--Praparation of methyl 1-ethyl-3-formylmethylene chloride-petroleum ether (B.P. 30-60 C.) to 5-methoxy-6-methyl-4,7-diox0-2-indolecarb0xylate give red-orange needles, M.P. 146148 C.

Ex m I 111427 In the manner described in Example 63 treatment of a p es 1 ethyl-3-formyl-5-hydroxy-6-methyl-4,7-dioxo-2-indole- In the manner described in Example 110 the products carboxylic acid (Example 131) with methyl sulfate and of Table XII are obtained. potassium carbonate in acetone produces a yellow oil.

TABLE XII l l 0 R2 Product Example No. Starting Material M.p., 0

R1 R2 R3 Product of Example 100... CH; H CH3 236-240 Product of Example 92.... CH3 CZHF, CH3 125-129 Product of Example 94.... OH: 03117 CH3 134-135 Product of Example 101... CH: CH(CH3)2 CH3 97-99 Product of Example 95.... CH; C H CH3 82.5-83.0 Product of Example 93.... CH: CzHa C2115 76.0-77.5 Product of Example 102... 02115 C2H5 CH3 83. 0-83 5 Product ofExamplc 99-.-- 0H orrzofizosoiorr 0H 143-144 i 119 Product of Example 97.--. CH3 02H; CHgOCCH; 142-144 120 Product of Example 96.--- CH OH H2011 128.5-130.0 Product of Example 103..- CH3 CHzCHzF CH3 114-117 Product of Example 105.-. CH3 CHzCI-IzNa CH3 80-81 Product of Example 106..- CH; OH2CH2SCN OH; (I) Product of Example 107... CH3 CHzCHzCl CH3 113.0-113.5 Product of Example 108... CH; CHgCHzSCH; CH 77- Product of Example 109.-- CH3 CH OH O CH3 129-131 Product of Example 98.... CH; 021.35 CONH; 197-199 1 Solid.

Example 128.-Preparati0n of 1 ethyl 5 methoxy 6- Example 133.Preparation of 1-ethyl-3-hydr0xymethylmethyl 4,7 dioxo 2 tetrahydropyranyloxymethyl- 5-methoxy-6-methyl-4,7-dioxoindole 3-" dol carb xaldeh de m 0 y A mlxture of 532 mg. (2.06 rnmoles) of l-ethyl-S-meth- A solution of 226 m of 1'elhyl'z'hydroxymethyl'5 oxy 6-methyl-4-nitro-3-indolecarboxaldehyde (Example methoxy-6-methyl-4,7-d1oxo-3-1ndolecarboxaldehyde (Ex- 60 7 and 0 mg f a Palladiumwmcharcoal cata ample 10 f 'P' l acld mono lyst in 100 ml. of ethanol containing 1 ml. of water is hy f and 92 of dlhydfopyran In of benzene shaken under hydrogen for 1 hour and minutes. A 13 stlfwd at TOOFH iemPeramfe for 3 hour? The 50111 pressure drop corresponding to 4 molar equivalents of tion 15 washed with sodium bicarbonate solution and then hydrogen is The mixture is filtered to give water, dried over sodium sulfate and evaporated to give an h li l i f 4- i -1- h l-3-h d h a Yellow yl-6-methyl-5-methoxyindole. This solution is added with Example 129.-Preparation of 5-meth0ucy-2,6-dimethylm stlrl'lng a Solution of of Potassium 4,7 dioxo 1 (t3 tetrahydropyranyloxyethyl) 3- mtrosodisulfonate in 40 m1. of water and 120 ml. of indolemrboxaldehyde M/ 6 potassium dihydrogen phosphate solution. The blue color is immediately discharged and within 10 minutes In t e manner dfisicflbed 111 EXample 128 treatment of an orange color develops. Stirring is continued for 80 1 (fl hydroxyethyl) 5 methOXY lm ylminutes, and the solution is diluted with water and 4,7 dioxo 3 indolecarboxaldehyde (Example 126) extracted thrice with methylene chloride. The organic with p-toluenesulfonic acid monohydrate and dihydrosolution is dried over magnesium sulfate and evaporated. The residue crystallizes from ether-petroleum ether (B.P.

pyran in ethyl acetate produces a red oil.

39 30-60" C.) to give 149 mg. of orange needles, M.P. 78-81 C.

Example J34.Preparatin of J-ethyl-S-hydroxymethyl- -meth0xy-2,6-dimethyl-4,7-di0x0ind0le 49 Example 153.Preparati0n 0] I -ethyl-4,5,6,7-tetrahydr0- 2-methyl-4-0x0indole A mixture of 33 g. of Z-acetonyl-1,3-icyclohexanedione [H. Setter and R. Lauterbach, Ann., 652, 43

In the manner described in Example 133 a solution of 1962)], of ethylamme 1 135 of methanol ethy1 5 methoXy 26 dimethyl 4 nitro 3 indolecarbOX 1s heated 1n a steel 'bomb at 150 C for 12 hours. The 1 drogen 1n the presence of a palladium-on-charcoal of meth lane chlorid a (1400 1 f t Th g i g to giveharll salcohghc 2 g Ta g 6 10 layer is washed two til nes wi t l l 5 s oil ium hi i ii d y roxymet y-- -met oxyrmet yin 0e. x1 ation of this substance with potassium nitrosodisulfonate if gigf gfifi i iz wg si d gi gh iiglgfigg g 11 confi g z 2222 2 iz g ggjg gf p 16 133 Produces red taining a small amount of ether. Recrystallization of this residue from cyclohexane affords 18.8 g. of l-ethyl- Example 135.Prepuration of methyl-1-ethyl-3-hydroxy- 4,5,6,7-tetrahydro-2-methyl-4-oxoindole, M.P. 74-75 C. Z 5 methoxy'6'm'e[Ml-4Zdwxmzdndolecar' Example ]54.-Preparati0n of 2,6-dim'ethyl-1-ethyloxy are 4,5,6,7-tetrahydr0-4-0xoindole In the manner described in Example 133 hydrogena- I p n the manner descrrbed 111 Exam le 153 treatment of non methyl 9 Z-aeetonyl-S-methyl-1,3-cyclohexanerfione [H. Stetter and tro-2-1ndolecarboxylate (Example 76) in the presence of Lautenbach Ann 652 43 (1962)] with ethyflamine a 10% palladium-on-charcoal catalyst gives an alcoholic gives White needles M P C solution of methyl 4 amino-1-ethyl-3-hydroxymethy1-5- methoxy-G-methyl-Z-indolecarboxylate. Oxidation of this Example 151-Preparation of 1-ethyl-4-hydroxysubstance with potassium nitrosodisulfonate in the manner Z-methylindole described in Example 133 produces yellow crystals, M.P. A mixture of 10 5 g of Labs/L46 6 7 tetrahydm 8O 82 Exam [es 136451 2-methyl-4-oxoindole (Example 153), 2.5 g. of 10% palp landi-um-on-charcoal and ml. of cumene is heated at In the manner described in Example 68 th compounds 30 reflux temperature for 3 hours, then cooled and filtered. of Table XIII are prepared, The filtrate is extracted with ml. of 5% sodium hy- TABLE XIII 0 ll omo more: R1 \N/ R: 6 1'1.

Product Example No. Starting Material M.p., 0.

R1 R3 R3 Product of Example 111"- CH3 H CH3 233-235 Product of Example CH3 CH5 CH3 Product 01 Example 113..- CH3 Cal-I1 CH: Product of Example 114 CH; CH(CH3)2 CH3 76-78 Product of Example 115 CH3 O4Hg CH3 68-70 Product of Example 116 CH3 C H rHs Product of Example 117..- CZHE 0 1-1 OH; 128-129 Product of Example 128... CH; 0 H; 11:

Product of Example 121... CH; CHZGHZF CH 116-118 Product of Example 122... CH; omomNa 011, Solid. Product of Example 123 CH3 CHZOHZSH CH3 Product of Example 124 0H3 OHiOHgCl OH; Product of Example 125 CH; CH CHzSCH: CH:

149 Product of Example 129.-- CH; CH3GHg0\0 CH;

150 Productof Example 132. CH3 02H; OOOCH; 83-84 151 Product of Example 127..- CH3 CZHE 0 ON H: 200-202 lndefinite.

2 Oil.

1 Solid.

Example 151-Preparation of mefhyl 1 70 droxide solution and this extract is layered with methylmethyl 5 methoxy'ls'methy ene chloride and carefully neutralized with acetic acid. boxylate The methylene chloride layer is Washed with sodium bi- In the manner described in Example 68 treatment of carbonate solution, dried and concentrated and the residue methyl 1 ethyl-3-formyl-5-methoxy-6-methyl-4,7-dioxois extracted with 500 ml. of boiling n-hexane. White 2-indolecarboxylate (Example 132) with sodium borohy- 75 crystals of 1-ethyl-4-hydroxy-2methylindole form on dride in methanol gives yellow crystals, M.P. 8284 C.

cooling the extract. They have M.P. 98-102 C. 

1. A MEMBER OF THE CLASS CONSISTING OF 3-(A-CARBAMOYLOXY-LOWER ALKYL)-4,7-IODOLOQUINONES OF THE FORMULA: 